Stoke Therapeutics, Inc. (NASDAQ: STOK) is a biotechnology company headquartered in Bedford, Massachusetts, pioneering the use of antisense oligonucleotides (ASOs) to selectively upregulate gene expression for the treatment of severe genetic diseases. The company's lead program, STK-001, is in Phase 2 development for Dravet syndrome — a devastating developmental and epileptic encephalopathy caused by SCN1A haploinsufficiency.
Stoke's mission is to address the root cause of severe genetic diseases by selectively increasing protein expression from the wild-type allele in patients with disease-causing loss-of-function mutations. Unlike traditional ASO approaches that target mRNA for degradation, Stoke's TANGO (Targeted Augmentation of Nuclear Gene Output) platform uses ASOs to restore levels of normally expressed but insufficient protein by increasing natural splicing of targeted transcripts.
The company's initial focus is on neurological diseases where increased expression of the wild-type allele can compensate for the loss of the mutant allele — a particularly compelling approach for conditions like Dravet syndrome where one functional copy of SCN1A is insufficient to prevent disease.
TANGO is a proprietary approach that uses allele-selective ASOs to increase natural mRNA splicing, thereby boosting production of the full-length, functional protein from the wild-type allele. Key features:
- Allele-selective: Targets only the wild-type allele for upregulation
- Splice-modulating: Redirects splicing to produce more full-length mRNA
- Disease-modifying: Addresses the underlying genetic cause rather than symptoms
- Repeatable: ASOs can be re-dosed, unlike AAV gene therapy
- ASO design: 18-20 base ASOs complementary to a specific sequence in the target pre-mRNA
- Splice redirection: Binding promotes spliceosome assembly at normally excluded exons
- Increased translation: More full-length mRNA → more functional protein
- Substrate specificity: TANGO ASOs do not affect mutant allele splicing
TANGO is applicable to any gene where:
- Haploinsufficiency causes disease
- Natural (non-altered) splicing products would be beneficial
- The gene has naturally occurring "poison exon" or alternative splice events
STK-001 is Stoke's lead product candidate for the treatment of Dravet syndrome, a severe developmental and epileptic encephalopathy characterized by treatment-resistant seizures, developmental delays, and significantly increased mortality risk.
Mechanism: STK-001 is an ASO that selectively increases SCN1A protein expression from the wild-type allele by promoting productive splicing of the target mRNA.
Clinical Development:
- Phase 1/2 (MONARCH): Dose escalation completed. Showed dose-dependent increases in SCN1A expression with acceptable safety profile
- Phase 2 (SEQUOIA): Dose confirmation ongoing, initiated 2024
- Phase 2 (BEACON, NCT05482706): Registration-directed study, initiated 2025
- Long-term extension (ALbatross): Ongoing for patients who completed Phase 1/2
Key Results (Phase 1/2 MONARCH):
- Dose-dependent increases in SCN1A mRNA in cerebrospinal fluid
- Encouraging seizure frequency reduction at higher doses
- Generally well-tolerated across dose range
- FDA granted Breakthrough Therapy Designation in 2024 based on preliminary evidence
Regulatory Status (March 2026):
- Breakthrough Therapy Designation active
- BLA preparation underway
- Q2-Q3 2026: Expected Phase 2 registration data readout
- Q4 2026: Anticipated BLA submission
STK-002 uses the same TANGO mechanism as STK-001 but is optimized for intrathecal delivery and may address different patient populations or administration preferences.
Status: Preclinical/IND-enabling
Stoke has announced pipeline expansion into other genetic diseases where TANGO could be applied:
- Undisclosed neurological target: Early discovery
- Undisclosed metabolic target: Preclinical evaluation
The company has indicated it is leveraging its platform to expand into additional monogenic diseases beyond Dravet syndrome.
| Metric |
Value |
| Exchange |
NASDAQ |
| Ticker |
STOK |
| IPO Date |
July 2020 |
| IPO Proceeds |
$125M |
| Market Cap |
~$800M-$1B (March 2026) |
| 2025 Follow-on |
$65M (Phase 2 BLA prep, manufacturing investment) |
| 2023 Follow-on |
$90M (STK-001/002 expansion) |
| Cash Position |
~$300M (estimated Q1 2026) |
| Employees |
~150-200 |
- 2020: IPO — $125M raised on NASDAQ
- 2023: Follow-on offering — $90M
- 2025: Follow-on offering — $65M for BLA preparation and manufacturing scale-up
- Catalyst-rich 2026: Phase 2 data and BLA preparation represent significant value inflection points
- Platform validation: Successful STK-001 would validate TANGO for broader application
- Risk: Single-program concentration — STK-001 failure would materially impact company
- Manufacturing: BLA requires significant GMP manufacturing investment, partially addressed with 2025 funding
Stoke competes in the Dravet syndrome therapeutic landscape with:
| Competitor |
Approach |
Stage |
| Encoded Therapeutics |
AAV gene activation (ETX101) |
Phase 1 |
| Ultragenyx (GeneTx) |
ASO for Angelman (GTX-102) |
Phase 2 |
| Roche/Neurocrine |
AAV gene therapy |
IND-enabling |
Advantages:
- Clinical data available (Phase 1/2 complete)
- FDA Breakthrough Therapy Designation
- ASO approach well-understood by regulators
- Repeatable dosing flexibility
Limitations:
- Requires repeat dosing (quarterly maintenance)
- Limited to allele-selective gain-of-function targets
- Intrathecal delivery (lumbar puncture) required
- Headquarters: Bedford, Massachusetts
- Leadership: Experienced biotech executives with rare disease and CNS expertise
- Board: Mix of scientific, financial, and industry expertise
- Scientific Advisory Board: Leading epilepsy and genetics researchers
¶ Key Publications and Presentations
- STK-001 Phase 1/2 MONARCH study results (Stoke Therapeutics, 2024)
- TANGO platform scientific rationale (Stoke Therapeutics, 2023)
- FDA Breakthrough Therapy Designation announcement (2024)
- Dravet syndrome ASO therapy - Nature Medicine perspective (2023)